Change-speed transmission



Dec. 25, 1951 w. P. SCHMITTER 2,579,869

CHANGE SPEED TRANSMISSION Filed Feb. 12, 1949 2 SHEETS-SHEET 1 M il'mae,

.zf ior/yeys Dec. 25, 1951 w. P. SCHMITTE CHANGE SPEED TRANSMISSION 2 SHEETS-SHEET 2 Filed Feb. 12, 1949 INVENTOR. Lam 1. 5%

jziorfzez r Y Patented Dec. 25, 1 951 CHANGE SPEED TRANSMISSION Walter" BaulmSchmitter, W'auwatosaa Wis; ass: signorr to i The Ealk; Corporation, Milwaukee, Wis.,acorporation of Wisconsin Application- February 12, 1949; Serial N6; 765030 changing I the tspacing. of c said elements through I rotatable adjustingshafts connected together by chain :drives whose distance" between centers re-w main constant? even though the distancevbetween CGIItBISJOf the "drive :and :driven :tunits is 1 variedi,

The invention further-consistsiiinathew'severale features hereinafterst: set; forth: andamorez: particularlyivdefined by claims at theiconclusionihere of; I.

In the drawings:

FigL- 1 is a side elevation ViGWTOIi: a"powertransamission; embodying? the invention, parts being broken L away I and rpartswbeingt shown in'sectiorr:

Fig: 2? is.;a=.:front elevationlview of the transmission, parts being broken away and parts being shown in section;

Fig; 3 is" a side elevationtviemqparts :being shown in a section taken generally along the line;-

3--3 of Fig 2- and showing,certaintmodifications in the motor mounting;

Fig? 4* is a vertical sectionalview taken alo'ng" thebroken line 4--4-of F1232? Fig. 5 is a detailed vertical sectional view' taken ontheline- 5-5- of Fig. 2.

Referring to the drawings, the numeral I designates generally a driven unit and 8 the drive motor. These parts are operatively connected together by a belt housing frame 9 which forms the support for the motor 8 and may be considered as part of the drive unit.

As shown in Fig. 1, the motor 8 has one of its end bells I secured to the frame 9 by bolts II. In Fig. 3 the frame 9 has an angled base plate I2 secured thereto by bolts I3 and the motor has base flanges I 4 bolted to the plate I2. In either case the motor 9 is suspended above the driven unit by an adjustable connection of the frame 9 with said unit.

The shaft I of the motor 8 carries a multiple adjustable groove V-belt pulley I6, and the shaft I? suitably mounted in bearings of the driven unit 1 carries a multiple adjustable groove V- belt pulley I8. Adjustable groove V-belt pulleys are old per se and embody pairs of groove formingelements, one elemen-t of eachipairi beingadj ustable' relative to the other to vary thei -distance? between said elements and hence the radial point: at which the V'-b"eltcontacts the groove so a as to s vary the drive ratio 1 between"- the drive: pulleys The pulleys I 6 and I a are 'opera-tivelyconnectedii together" by belt's I 9*mounted in alined grooves: of said" pulleys."-

The adjustable connection between: the: frame; S and thedrivemun-it permits movin'g the units towardor away from ea'ch other to-accommodate the adjustment of the pulleys and permit the tem si'oning of the belts I95 Thisconnectionincludes four stud-s provided with nuts I equidistantlyp-r radially spaced from the center of the 1 driven-z: shaft I1 and"anch0red'in a part'ZI of the-Iframe's of-'-'the 1 driven unit I and- "extending :throughiarcuate slots22 inthe frame 9. 1 Ericirc'ling these1b'olts;

is a-turn'able ring 23 which has-*a hole 24 onits" horizontal axis and a-threaded hole 25Wdiametri+ call y opposite the hole 24 m which 1 a bolt Zil iso anchored; said bolt-passingthroughaeeholevzl' by a spacer ring 'zli.

bore of a -nut 3 I which has a proj ection- 32 engage: ingrloosely in the -ho le fiz Since the .jack screwais mounted diiectly on the frame 9? 'andcarr-.-

ries the nut 3| whose projection 32 engagesathel I ring 23Qmovement= of' thenut- 31 along the screw 3ll will rotate 01* turn said ring relative ito: thec fixed unit I. With this arrangement on a slight loosening of the nuts 20 turning of the squared end 33 of the jack screw 30 to move the nut 3| to exert a downward thrust on the ring 23 turns the same and moves the bolt 26 up from the position shown in Fig. 2 and consequently through the contact of said bolt 26 with the frame 9 moves this side of the frame 9 up with it. At the same time when the frame moves up on the bolt side 26, the distance of the nut 3I from the upper support 29 is increased, thus moving the other side of the frame up an amount corresponding to the movement of said frame by said ring. This upward movement of the frame 9 is caused by the upward reaction thrust exerted 'by the jack screw 30 on the support 29 carried by said frame. Turning of the screw 30 to move the nut 3i to exert an upward thrust on the ring 23 turns the same and moves the bolt 26 down from the posi-- tion shown in Fig. 2 and consequently through the contact of the bolt 26 with the frame 9 moves this side of the frame down while the distance of the nut 3| from the lower support 29 is increased, thus moving this side of the frame downwardly an amount corresponding to the downward movement of said frame by said ring. This downward movement of the frame 9 is caused by the downward reaction thrust exerted by the jack screw 39 on the support 29 carried by said frame. Thus by the direct connection of the jack screw 30 with one side of the frame 9 and its indirect connection with the other side of said frame through the nut 3| and the ring 23 which carries the bolt 26 mounted in the hole 21 in the frame 9 turning of the screw 39 moves the frame 9 up or down to vary the distance between the drive shaft l and the driven shaft After the desired adjustment has been obtained, the nuts 29 are tightened up to maintain the adjustment. The adjustable elements of V-belt pulleys l6 and I8 are in known manner moved to their adjusted positions by rotatable operating shafts 34 and 35, and in order that these shafts may be turned simultaneously they are geared or operatively connected together by chain and sprocket gearing, and in order that this gearing may comprise chains of fixed length the shafts 34 and 35 are connected by chain gearing with a shaft extension 38 of the bolt 26. As shown the shaft 34 carries a sprocket 39 connected by a chain 49 with a sprocket 4| journalled on the extension 38 while the shaft 35 carries a sprocket 42 connected by a chain 43 with a sprocket 44 integral with or connected to the sprocket 4| so that by turning the shaft 34 by a removable hand crank the shafts 34, 38 and 35 are turned simultaneously through the chain and sprocket gearing above described to adjust the adjustable elements of the V-belt pulleys I6 and I8. In this connection it will be noted that since the shaft extension 38 is mounted on the ring 23 which has the same axis or center as the shaft |5 its distance does not change when the ring 23 isturned to move the bolt 26 with said shaft 38 up or down as previously described, and since the bolt 26 moves up or down the same amount that the frame 9 carrying the shaft moves up or down, the distance between the shaft I! and the shaft extension 38 does not change. Thus the anchoring of the support for the sprockets 4| and 44 on the ring keeps the lengths of the drive connections for the pulley adjustments constant and thus simplifies the construction. V

' While the adjustable feature above described is especially desirable for adjustable V-belt pulleys,

it is to be noted that it may be used with transmissions having non-adjustable pulleys and that other changes may be made without departing from the invention which is not to be limited to the specific details hereinbefore described except as such limitations are included in the appended claims.

What I claim as my invention is:

1-. In a change speed transmission having a drive unit and a driven unit and a belt drive connection between said units, one of said units being a movable unit having an adjustable sup-.- porting mounting on the other fixed unit, mechanism for moving said units relative to each other to adjust the tension of said belts comprising a member rotatably mounted on said fixed unit and directly connected to one side of said supporting unit for movement of this side of said unit, and manually adjustable means on the other side of said supporting unit indirectly connected to said member for moving said member and this side. of said unit. 3:

2. In a change speed transmission having a drive unit and a driven unit and a belt drive connection between said units, one of said units having an adjustable supporting mounting on the other unit, mechanism for moving said units relative to each other to adjust the-tension of said belts comprising a jack screw carried by said supporting mounting at one side thereof, a member rotatably mounted on said other unit, a nut engaging said jack screw and operatively connected with said member to angularly shift the same, and a member carried'by said rotatable member and on the opposite side thereof from the nut and having a load supporting connection with REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Date Number Name 1,353,986 Bergendorf Sept. 28, 1920 1,482,013 Jarvis et al Jan. 29, 1924 1,488,617 Robinson 1 Apr. 1, 1924 

